You Harry L. 4

What Happened
Harry L. You (reported as a 10% owner and managing member of dMY Squared Sponsor, LLC) acquired equity in Horizon Quantum Holdings Ltd. on 2026-03-19 as part of the closing of the business combination with dMY Squared Technology Group, Inc. He received 1,163,484 Class A ordinary shares (issued in exchange for DMY Class A shares) and 2,884,660 warrants (issued in exchange for DMY warrants). The filing lists no purchase price for HQ securities (Acquired, code A); using DMY’s closing prices on the effective date implies approximate values of $15.71M for the shares (1,163,484 × $13.50) and $7.76M for the warrants (2,884,660 × $2.69), total ≈ $23.47M.

Key Details

• Transaction date: 2026-03-19; Form 4 filed 2026-03-20 (appears timely).
• Reported transaction type/code: A = Grant/Award/Other acquisition. Warrants reported as derivative securities.
• Shares/warrants acquired: 1,163,484 Class A shares; 2,884,660 warrants.
• Prices reported on Form 4: N/A (securities were issued in exchange under the business combination). DMY closing prices used for implied value: $13.50 (DMY Class A) and $2.69 (DMY warrants).
• Shares owned after transaction: Not specified for HQ in the provided filing; the Sponsor is the record holder.
• Notable footnotes: The HQ securities were issued pursuant to the Business Combination Agreement in exchange for DMY securities (Footnotes F1, F2). dMY Squared Sponsor, LLC is the record holder and Harry L. You is the managing member with voting and investment discretion; both the Sponsor and Mr. You are Reporting Persons and disclaim beneficial ownership except to the extent of any pecuniary interest (F3).
• Exemption/filing note: Because HQ is a foreign private issuer, these transactions are reported as exempt from Sections 16(b) and 16(c) under Rule 3a12-3(b) (Remarks).

Context

• This was not an open-market buy or sale but an issuance in connection with a merger/business combination; the securities were received in exchange for DMY securities rather than a cash purchase.
• Warrants are derivative instruments; the filing reports them as acquired via exchange (not as exercised).
• As a 10% owner and sponsor representative, Mr. You’s report reflects institutional/transactional ownership tied to the Sponsor structure rather than a typical executive open-market trade.